/Engine/Plugins/Runtime/Metasound/Source/MetasoundFrontend/Public/MetasoundFrontendController.h
Adds a duplicate subgraph to the document. This method creates a copy of the graph and adds all the graph dependencies to this document.
Handle to new graph. On error, an invalid handle is returned.
[FGraphHandle](API\Plugins\MetasoundFrontend\FGraphHandle) AddDuplicateSubgraph ( const [IGraphController](API\Plugins\MetasoundFrontend\IGraphController) & InGraph )